/**
  @file
  @author Stefan Frings
*/

#include "filelogger.h"
#include <QTime>
#include <QStringList>
#include <QThread>
#include <QtGlobal>
#include <QFile>
#include <QTimerEvent>
#include <QDir>
#include <QFileInfo>
#include <stdio.h>

void FileLogger::refreshSettings() {    
    mutex.lock();
    // Save old file name for later comparision with new settings
    QString oldFileName=fileName;

    // Load new config settings
    settings->sync();
    fileName=settings->value("fileName","./server/logs/log.log").toString();
    // Convert relative fileName to absolute, based on the directory of the config file.
#ifdef Q_OS_WIN32
    if (QDir::isRelativePath(fileName) && settings->format()!=QSettings::NativeFormat)
#else
    if (QDir::isRelativePath(fileName))
#endif
    {
        QFileInfo configFile(settings->fileName());
        fileName=QFileInfo(configFile.absolutePath(),fileName).absoluteFilePath();
    }
    maxSize=settings->value("maxSize",0).toLongLong();
    maxBackups=settings->value("maxBackups",0).toInt();
    msgFormat=settings->value("msgFormat","{timestamp} {type} {msg}").toString();
    timestampFormat=settings->value("timestampFormat","{yyyy-MM-dd hh:mm:ss.zzz}").toString();
    minLevel=static_cast<QtMsgType>(settings->value("minLevel",0).toInt());
    bufferSize=settings->value("bufferSize",0).toInt();
    disabled=settings->value("disabled",false).toBool();

    // Create new file if the filename has been changed
    if (oldFileName!=fileName) {
        fprintf(stderr,"Logging to %s\n",qPrintable(fileName));
        close();
        open();
    }
    mutex.unlock();
}


FileLogger::FileLogger(QSettings* settings, const int refreshInterval, QObject* parent)
    : Logger(parent)
{
    //Q_ASSERT(settings!=0);
    //Q_ASSERT(refreshInterval>=0);
    this->settings=settings;
    file=0;
    if (refreshInterval>0)
        refreshTimer.start(refreshInterval,this);
    flushTimer.start(1000,this);
    refreshSettings();
}


FileLogger::~FileLogger() {
    close();
}


void FileLogger::write(const LogMessage* logMessage) {
    // Write to the file
    if (!disabled) {
        // Try to write to the file
        if (file) {

            // Write the message
            file->write(qPrintable(logMessage->toString(msgFormat,timestampFormat)));

            // Flush error messages immediately, to ensure that no important message
            // gets lost when the program terinates abnormally.
            if (logMessage->getType()>=QtCriticalMsg) {
                file->flush();
            }

            // Check for success
            if (file->error()) {
                close();
                qWarning("Cannot write to log file %s: %s",qPrintable(fileName),qPrintable(file->errorString()));
            }

        }

        // Fall-back to the super class method, if writing failed
        if (!file) {
            Logger::write(logMessage);
        }
    }

}

void FileLogger::open() {
    if (fileName.isEmpty()) {
        qWarning("Name of logFile is empty");
    }
    else {
        file=new QFile(fileName);
        if (!file->open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text)) {
            qWarning("Cannot open log file %s: %s",qPrintable(fileName),qPrintable(file->errorString()));
            file=0;
        }
    }
}


void FileLogger::close() {
    if (file) {
        file->close();
        delete file;
        file=0;
    }
}

void FileLogger::rotate() {
    // count current number of existing backup files
    int count=0;
    forever {
        QFile bakFile(QString("%1.%2").arg(fileName).arg(count+1));
        if (bakFile.exists()) {
            ++count;
        }
        else {
            break;
        }
    }

    // Remove all old backup files that exceed the maximum number
    while (maxBackups>0 && count>=maxBackups) {
        QFile::remove(QString("%1.%2").arg(fileName).arg(count));
        --count;
    }

    // Rotate backup files
    for (int i=count; i>0; --i) {
        QFile::rename(QString("%1.%2").arg(fileName).arg(i),QString("%1.%2").arg(fileName).arg(i+1));
    }

    // Backup the current logfile
    QFile::rename(fileName,fileName+".1");
}


void FileLogger::timerEvent(QTimerEvent* event) {
    if (!event) {
        return;
    }
    else if (event->timerId()==refreshTimer.timerId()) {
        refreshSettings();
    }
    else if (event->timerId()==flushTimer.timerId() && file) {
        mutex.lock();

        // Flush the I/O buffer
        file->flush();

        // Rotate the file if it is too large
        if (maxSize>0 && file->size()>=maxSize) {
            close();
            rotate();
            open();
        }

        mutex.unlock();
    }
}
